Saw chain lubrication means

ABSTRACT

Disclosed herein is a chain saw cutter bar including two side plates having respective inside surfaces defining therebetween a groove adapted for receiving the tangs of a saw chain, together with means in one of the side plates defining a lubrication hole communicating with an oil supply conduit in a supporting chain saw powerhead and including a merging surface which extends in the general direction of intended chain travel and relative to the inside surface of the one side plate at an obtuse angle, whereby to discourage sawdust accumulation in the lubrication hole while affording lubricant flow to the saw chain.

United States Patent i1 1 [111 3,840,991

Arff et al. Oct. 15, 1974 l54l SAW CHAIN LUBRICATION MEANS 2,755,826 7/!956 Kickhncfcr i. 83/169 X 5 .4 [75] Inventors: Uwe F. Arff; G0rd0n J. Edwards, 2'827937 m9 8 Smmk both of Peterborough, Ontario, C d Primary Examiner-Donald R. Schran Attorney, Agent, or FirmMichaell, Best & Friedrich [73] Asslgnee: Outboard Marine Corporation,

Waukegan, Ill. 22 Filed: May 17, 1973 [57] ABSTRACT 2 1 App]- 3 1 7 Disclosed herein is a chain saw cutter bar including 0 two side plates having respective inside surfaces defin- Related Apphcanon Data ing therebetween a groove adapted for receiving the [62] Division of Ser. No. 183,998, Sept. 27, 1971, Pat. tangs of a saw chain, together with means in one of the side plates defining a lubrication hole communicating with an oil supply conduit in a supporting chain Cl 134/15 R saw powerhead and including a merging surface which i extends in the general direction of intended chain Fleld of Search 333/169; 184/15 R; 30/381, travel and relative to the inside surface of the one side 30/332, 383, 384, 386, 387 plate at an obtuse angle, whereby to discourage sawdust accumulation in the lubrication hole while affordl References Cited ing lubricant flow to the saw chain.

UNITED STATES PATENTS 2,748,810 6/1956 Strunk 30/387 x 5 Chums 9 Drawmg lF'gures SAW (II-IAIN LUBRICATION MEANS This is a division of application Ser. No. 183,998 filed Sept. 27, 1971 now U.S. Pat. No. 3,777,401.

BACKGROUND OF THE INVENTION Chain saws have been provided with arrangements for supplying oil to lubricate the saw chain traveling in the peripheral groove of a cutter bar. Such arrangements have commonly included a transverse aperture or oil duct in one of the cutter bar side plates or rails', which aperture at least partially communicates with the peripheral groove and with an oil supply conduit provided in the chain saw powerhead.

The transverse aperture or duct extended generally perpendicularly to the plane of the cutter bar and provided a surface or shoulder which also extended generally perpendicularly of the inside surface of the rail in a manner to afford collection and accumulation of wood chips or sawdust in the oil duct. Such accumulation of wood chips and sawdust could eventually clog the oil duct and was undesirable.

SUMMARY OF THE INVENTION More specifically, the invention provides a cutter bar 1 including a lubrication hole having a wall surface which merges with one of the groove defining surfaces at an angle greater than 90, whereby to avoid formation of a surface which could serve to facilitate sawdust accumulation.

Still more specifically, in one embodiment of the invention, the lubrication hole is provided by a cylindrical passage which is inclined toward the peripheral cutter bar groove in the direction of chain travel and which is additionally inclined outwardly in the direction toward the periphery of the cutter bar from the outside surface of the bar to an outlet in the cutter bar groove.

In another embodiment of the invention, there is provided an insert which is adapted to be placed in an existing oil duct of a prior art cutter bar and which is formed to provide a lubrication hole with a wall or surface merging with one of the surfaces defining the cutter bar groove so as to avoid accumulation in the lubrication hole of wood chips or sawdust, and thereby prevent clogging of the oil passage to the cutter bar groove.

One of the principal objects of the invention is the provision of a cutter bar provided with a non-sawdust clogging arrangement for supplying oil to the cutter bar groove and ultimately to the saw chain.

Another of the principal objects of the invention is the provision of a chain saw including a system for supplying oil to the saw chain, which system is not subject to clogging by wood chips and sawdust.

Another of the principal objects of the invention is the provision of an arrangement affording ease of modification of existing chain saws and cutter barsto provide a lubrication hole having a surface merging with one of the surfaces defining the cutter bar groove so as to avoid any tendency for sawdust accumulation in the system for supplying oil to the saw chain.

Still another object of the invention is the provision of a non-clogging system for supplying oil to the peripheral groove of a cutter bar, which system can be readily and economically manufactured and which will not easily clog up with sawdust or wood chips and which will provide reliable service over a long and useful life.

Other objects and advantages of the invention will become known by reference to the following description and accompanying drawings.

DRAWINGS FIG. 1 is a fragmentary sectional view of a portion of a chain saw embodying various of the features of the invention.

FIG. 2 is a fragmentary elevational view, with parts omitted, and with portions broken away, taken from the left of FIG. 1 and illustrating one embodiment of a cutter bar formed in accordance with the invention.

FIG. 3 is an enlarged fragmentary sectional view of a portion of the chain saw illustrated in FIG. 1.

FIG. 4 is a fragmentary sectional view taken generally along'line 4-4 of FIG. 3.

FIG. 5 is an enlarged fragmentary elevational view of a portion of the cutter bar shown in FIG. 2.

FIG. 6 is a view similar to FIG. 2 illustrating a cutter barin accordance with another embodiment of the invention.

FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 6. y

FIG. 8 is a fragmentary, enlarged view of'a portion of the cutter barshown in FIGS. 6 and 7.

FIG. 9 is an enlarged fragmentary view, partially in section, of another construction embodying various of the features of the invention.

Before explaining the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts set forthin the following detailed description or illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. i

-. DETAILED DESCRIPTION Fragmentarily illustrated in FIG. 1 is a chain saw 11 comprising an engine casting or chain saw frame or powerhead 13 including a cutter bar mounting surface 117 from which extends a pair of cutter bar mounting posts 119 (only one of which is shown in FIG. 1). The chain saw 11 also'includes a guide plate 21 which is received on the mounting posts 19 and a cutter bar 23 which is located exteriorly of the guide plate 21 with the mounting posts 19 extending in an elongated mounting slot 27. The cutter bar 23 includes two spaced rails or side plates 29 which respectively include peripheral surfaces 31 adapted to provide bearing sup port for the links of a saw chain 33 (shown fragmentarily in FIG. 2), together with respective outside and inside surfaces 37 and 39. Defined between the inside surfaces 39 is a peripheral slot or groove 41 which includes a bottom wall or surface 43 and which is adapted to receive the drive or other tangs of the saw chain 33. As thus disclosed, the construction is conventional.

In accordance with the invention, there is provided a saw chain lubricating system which is especially adapted to prevent an oil blocking build-up of wood chips or sawdust while simultaneously affording a reliable supply of oil to the saw chain. The lubricating system includes, in the powerhead 13, an oil supply conduit 47 which communicates with a suitable oil pump (not shown) and which terminates in the cutter bar mounting surface 17, together with means in the adjacent rail or side plate 29 of the cutter bar 23 defining a lubrication hole 49 which includes an inlet located in the outside surface 37 and communicating with the oil supply conduit 47, which further includes an outlet located in the inside surface 39 and communicating with the groove 41, and which still further includes a merging surface 51 which, in the direction of intended chain travel, indicated by the arrow 53 in FIGS. 2 and 4, extends to and in inclined relation to the inside rail surface 39, whereby such merging relation avoids sawdust accumulation in the outlet into the groove 41 of the lubrication hole 49. I

Various arrangements can be provided to provide such a merging surface so as to avoid a surface which is substantially transverse in relation to the direction of travel and located in such position whereby wood chips and sawdust can lodge thereagainst. In the construction shown in FIGS. 1 through 5, the merging wall surface 51 (See FIG. 4) is provided by formation of the lubrication hole 49 with a drill and at an angle 57 which extends, as shown in FIG. 4, at approximately 30 to the direction of intended chain travel as indicated by the arrow 53. As a consequence of the angular inclination of the lubrication hole just mentioned, the merging surface, seen at 51 in FIG. 4, is provided.

In order to locate the outlet as close to the periphery of the cutter bar 23 as possible, and without adversely affecting the capability for hardening of the peripheral surface 31, the lubrication hole 49 is also preferably drilled from the outside surface 37 at an angle of about 30 as seen at 59 in FIG. 3. As a result of the inclinations described above and shown best in FIGS. 3 and 4, the resulting lubrication hole 49 extends obliquely as illustrated in FIGS. 2 and 5 to thereby provide a rising oil passage or lubrication hole which extends at an angle 60 of about 45 as shown in FIG. 5. Employment of such an inclined lubrication hole serves tolocate the inlet at a maximum distance from the peripheral rail surface consistent with locating the outlet as far as possible from the groove bottom wall 43. Preferably, the outlet is wholly formed in the side rail inside surface 39 and as close as possible to the peripheral rail surface 31. Such construction affords complete wiping of the outlet by the chain tangs to assist in avoidance of accumulation of sawdust.

Also in accordance with the invention, and in order to insure communication with the oil supply conduit 47, notwithstanding adjustment of the cutter bar is in relation to the powerhead 13 to adjust chain tension, the inlet of the lubrication hole 49 is provided with an enlarged well 61 which extends from the inlet in the outside rail surface 37 in the general direction counter to the direction of intended chain travel and inwardly or away from the outer periphery of the cutter bar. Such a well can be economically provided in the rail or side plate by a coining operation during the rail blanking operation. In addition, the oil supply conduit 47 in the powerhead 13 is preferably provided with an enlarged mouth or well 63 which can be elongated in the direction parallel to the adjustment slot 27 (see FIG. 2), thereby to provide for continued communication between the lubrication hole 49 and the oil supply conduit 47, notwithstanding adjustment in the location of the cutter bar 23 relative to the powerhead 13. Still further, a suitable bore, opening or slot 67 is provided in the guideplate 21 to afford communication between the well 61 and inlet and the oil supply conduit 47. This slot 67 can, if desired, be elongated in the direction of cutter bar adjustment to provide for continued communication between the lubrication hole inlet and the oil supply conduit 47, notwithstanding the before mentioned adjustment of the cutter bar 23. With such an elongated slot, the mouth 63 could be formed without material elongation in the direction of cutter bar adjustment. Depending upon the elongation of either the slot 67 or the mouth 63, the location of the lubrication hole can be varied as desired in the direction of cutter bar adjustment.

Preferably, the cutter bar 23 is provided with'a duplicate or second lubrication hole 69 similarly located and constructed in the other rail and on the other side of the mounting slot 27.

The invention also extends to arrangements including location of the lubrication hole in the'opposite side rail, i.e'., in the side rail opposite from the powerhead 13, and to provision of a suitable engagement for supplying oil to the lubrication hole oil inlet in the side plate remote from the powerhead 13.

FIGS. 6, 7, and 8 are illustrative of another arrangement which is in accordance'with the invention and which includes a cutter bar 77 having spaced side plates or rails 79 with respective peripheral surfaces 81, outside surfaces 83, and inside surfaces 87 which define therebetween a groove 89 having a bottom wall or surface 91. The cutter bar 77 also includes a mounting slot 93 and pair of spaced apertures 97 which extend transversely through the rails 79 and, at least in part, communicates with the groove 89. In the construction specifically disclosed in FIGS. 6, 7, and 8, the apertures 97 extend at a right angle to the plane of the cutter bar 77 and are elongated along a line extending perpendicularly to the mounting slot 93 and have semicircular end portions 99. Approximately the outer half of each aperture 97, i.e., the half closest to the peripheral surface 87, opens into the groove 89. The other or inner half of each aperture 97 is blind. When the cutter bar 77 is assembled to a powerhead, one of the apertures 97 is adapted to communicate with an oil supply conduit (not shown). As thus far described, the construction of the cutter bar 77 of FIGS. 6, 7, and 8 is conventional.

In accordance with the invention, means are provided for modifying existing cutter bars to provide lubrication holes in accordance with the invention. While various arrangements can be employed in accordance with the invention, in the construction disclosed in FIGS. 6, 7, and 8, such means includes provision in the aperture 97 communicating with the oil supply conduit of a lubrication hole 121 which includes a surface 123 in merging relation with the inside rail surface 87 and which includes an outlet 127 in co-planar relation to the inside rail surface 87, and an inlet 129 communicating with the aperture 97. Specifically, in the construc- I tion shown in FIGS. 6, 7, and 8, such means comprises an insert 131 received in the bore or aperture 97 and having a flat portion 133 defining a planar surface 135 located in co-planar relation to the inside rail surface 87, together with a peripheral flange 139 which extends from the flat portion 135, generally mates with the wall defining the aperture 97, and has a length approximately equal to the width of the side rail or plate 83. The insert 131 also includes a merging wall portion 111 which provides the merging wall surface and which is formed out of the flat portion 133 and extends from the flat portion 133. More specifically, the merging wall portion 111 extends at a relatively small acute angle 143 from the flat portion and in a manner such that the distance of the merging wall portion M1 from the plane of the flat portion 133 increases in the direction counter to the direction of intended chain travel indicated by the arrow 147 in FIG. 7. At its outer or free end, the merging wall portion 141 defines, together with the margin of the flat portion 133, the lubrication hole inlet 129 which communicates with the volume or space at the back side of the merging wall portion 141 and within the confines of the flange portion 133. As already indicated, this space communicates with an oil supply conduit (not shown) in the engine casting or powerhead, and constitutes an oil reservoir affordingample oil supply to the lubrication hole 121. The area within the margin of the flat portion 133 from which the merging wall portion 111 has been formed constitutes the lubricating hole outlet 127 to the groove 39.

The insert 131 can be provided with a dimple 1419 to indicate the proper orientation of the insert 131 in the bore, i.e., location in the aperture 97 such that the merging wall portion 141 inclines toward the flat portion 133 of the insert 131 in the direction 117 of intended chain travel.

During travel of the chain in the groove of the cutter bar 77 shown in FIGS. 6, 7, and t3, the chain saw tangs successively wipe or travel past the outlet 127 in such manner as to provide a venturi-like effect and to draw oil into the peripheral groove 89 due to such passage. The angular relationship between the merging wall surface 123 and the flat portion 133 which is co-planar to the inside surface 97 of the rail, serves to prevent sawdust accumulation in the lubrication hole 121.

Shown fragmentarily in F116. 9 is still another construction of a lubrication hole 151 provided ina cutter bar 153 in general accordance with the invention. More specifically, the cutter bar 153 shown fragmentarily in FIG. 9 includes a rail or side plate 157 having an outer or outside surface 159 and an inner or inside surface 161 forming one wall of a groove 163 adapted to receive the tangs of a saw chain (not shown). As in the embodiment shown in FIGS. 6, 7, and 8, the rail 157 includes an oil duct or aperture 167. Provided in the oil duct or aperture 167 are a larger insert 169 and a smaller insert 171 which are located in facing relation to each other and which define therebetween the lubrication hole 151 and additionally provide a merging wall or surface 173.

More specifically, the larger insert 169 includes a fiat portion 175 and a flange portion 179 extending from the flat portion 175 and having an over-all height approximately equal to the width of the rail 157 so that the surface of the flat portion 175 is co-planar with the inside rail surface 161. Provided interiorly of the flat portion 175 is a bent portion 181 which is cut out of the flat portion 175, which extends from the flat portion 175 and which provides the merging wall or surface which extends at an angle to, and at an ever increasing distance away from, the inside surface 161 in the direction counter to the direction of intended chain travel indicated by the arrow 183.

The smaller insert 171 comprises a similarly shaped disc having a central portion 167 and a flange portion 189 which extends from the central portion 167 and is matingly received inside of the flange portion 179 of the larger insert 169 and which has an over-all height generally equal to the width of the side rail 157 less the thickness of the flat portion 175 of the larger insert 169. Provided interiorly of the central portion 1117 is a bent portion 191 which is cut from and formed out of the central portion 187 and which extends, when the smaller insert 171 is located in the larger insert 169, in generally parallel relation to the merging wall surface 173 so as to define, together with the merging wall surface 173, the lubrication hole 151.

If desired, the bent portion 191 of the smaller insert 171 can be formed so as to provide, in conjunction with the larger insert bent portion 173, an oil passage or lubrication hole which can either increase or decrease in size in the direction of chain travel. Of course, the inlet end of the lubrication hole 151 communicates with a suitable oil supply conduit (not shown) in the powerhead and the outlet of the lubrication hole 151 is generally located adjacent to the plane of the inside cutter bar surface 161 with the merging; surface or wall 173 forming an angle 193 with the inside rail surface 161 of greater than and preferably as great as about Various of the features of the invention are set forth in the following claims.

What is claimed is:

1. A chain saw bar for guiding travel of a saw chain, said bar including two peripheral rails having respective inside surfaces defining therebetween a groove adapted for receiving the tangs of the saw chain, one of said rails including an aperture and an insert in said aperture, said insertincluding means defining a lubrication hole communicating with said groove and including a merging surface which, in the generaldirection of intended travel of the saw chain, extends to and in inclined relation to said groove, whereby to discourage sawdust accumulation in said lubrication hole.

2. A chain saw bar in accordance with claim 1 wherein said aperture is elongated in the direction transverse to the direction of intended chain travel.

3. A chain saw bar in accordance with claim 1 wherein said insert comprises a disc with a surface generally co-planar with said inside surface of said one rail, said disc also having a peripheral flange mating with the wall of said aperture.

4. A chain saw bar in accordance with claim 3 wherein said disc includes a portion which is bent outwardly from the plane of said inside surface to provide said lubrication hole merging surface.

5. A chain saw bar in accordance with claim 4 wherein said portion extends, in the direction counter to the direction of intended chain travel, at a gradually increasing distance from said inside surface of said one 

1. A cHain saw bar for guiding travel of a saw chain, said bar including two peripheral rails having respective inside surfaces defining therebetween a groove adapted for receiving the tangs of the saw chain, one of said rails including an aperture and an insert in said aperture, said insert including means defining a lubrication hole communicating with said groove and including a merging surface which, in the general direction of intended travel of the saw chain, extends to and in inclined relation to said groove, whereby to discourage sawdust accumulation in said lubrication hole.
 2. A chain saw bar in accordance with claim 1 wherein said aperture is elongated in the direction transverse to the direction of intended chain travel.
 3. A chain saw bar in accordance with claim 1 wherein said insert comprises a disc with a surface generally co-planar with said inside surface of said one rail, said disc also having a peripheral flange mating with the wall of said aperture.
 4. A chain saw bar in accordance with claim 3 wherein said disc includes a portion which is bent outwardly from the plane of said inside surface to provide said lubrication hole merging surface.
 5. A chain saw bar in accordance with claim 4 wherein said portion extends, in the direction counter to the direction of intended chain travel, at a gradually increasing distance from said inside surface of said one rail. 